/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.catalina.ha.session;

import org.apache.catalina.ha.ClusterListener;
import org.apache.catalina.ha.ClusterManager;
import org.apache.catalina.ha.ClusterMessage;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;

import java.util.Map;

/**
 * Receive replicated SessionMessage form other cluster node.
 *
 * @author Filip Hanik
 * @author Peter Rossbach
 */
public class ClusterSessionListener extends ClusterListener {

	/**
	 * The descriptive information about this implementation.
	 */
	protected static final String info = "org.apache.catalina.ha.session.ClusterSessionListener/1.1";
	private static final Log log =
			LogFactory.getLog(ClusterSessionListener.class);

	//--Constructor---------------------------------------------

	public ClusterSessionListener() {
		// NO-OP
	}

	//--Logic---------------------------------------------------

	/**
	 * Return descriptive information about this implementation.
	 */
	public String getInfo() {

		return (info);

	}

	/**
	 * Callback from the cluster, when a message is received, The cluster will
	 * broadcast it invoking the messageReceived on the receiver.
	 *
	 * @param myobj ClusterMessage - the message received from the cluster
	 */
	@Override
	public void messageReceived(ClusterMessage myobj) {
		if (myobj != null && myobj instanceof SessionMessage) {
			SessionMessage msg = (SessionMessage) myobj;
			String ctxname = msg.getContextName();
			//check if the message is a EVT_GET_ALL_SESSIONS,
			//if so, wait until we are fully started up
			Map<String, ClusterManager> managers = cluster.getManagers();
			if (ctxname == null) {
				for (Map.Entry<String, ClusterManager> entry :
						managers.entrySet()) {
					if (entry.getValue() != null)
						entry.getValue().messageDataReceived(msg);
					else {
						//this happens a lot before the system has started
						// up
						if (log.isDebugEnabled())
							log.debug("Context manager doesn't exist:"
									+ entry.getKey());
					}
				}
			} else {
				ClusterManager mgr = managers.get(ctxname);
				if (mgr != null) {
					mgr.messageDataReceived(msg);
				} else {
					if (log.isWarnEnabled())
						log.warn("Context manager doesn't exist:" + ctxname);

					// A no context manager message is replied in order to avoid
					// timeout of GET_ALL_SESSIONS sync phase.
					if (msg.getEventType() == SessionMessage.EVT_GET_ALL_SESSIONS) {
						SessionMessage replymsg = new SessionMessageImpl(ctxname,
								SessionMessage.EVT_ALL_SESSION_NOCONTEXTMANAGER,
								null, "NO-CONTEXT-MANAGER", "NO-CONTEXT-MANAGER-" + ctxname);
						cluster.send(replymsg, msg.getAddress());
					}
				}
			}
		}
		return;
	}

	/**
	 * Accept only SessionMessage
	 *
	 * @param msg ClusterMessage
	 * @return boolean - returns true to indicate that messageReceived should be
	 * invoked. If false is returned, the messageReceived method will
	 * not be invoked.
	 */
	@Override
	public boolean accept(ClusterMessage msg) {
		return (msg instanceof SessionMessage);
	}
}

